Graham said the victim refused to pay him the money, and he shot Casterman once in the back of the head.

He called a mutual friend, informing her that he just killed Casterman.

“The friend did not believe Graham, so he texted her a picture of Casterman’s body,” the statement said.

Graham then went to a different friend’s house and forced him at gunpoint to help dispose of the body, prosecutors said. Graham drove in the victim’s car to West Blocton, Ala., and dumped the body in a tree-lined area.

The next day, Graham’s girlfriend and her mother got Facebook messages informing them of Casterman’s disappearance and Graham’s suspected involvement. The mother called authorities and Graham was subsequently arrested.

He then admitted to the murder and told investigators where the body was located.